Trencher



April 1957 E. M. RILEY ETAL TRENCHER Filed Sept. 2, 1950 2 Sheets-Sheet 1 INVENTORS. [kW/IV M ,Q/zsy ATTORNE Y- April 30, 1957 M. RILEY ET AL 2,790,255

TRENCHER Filed Sept. 2, 1950 2 Sheets-Sheet 2 United States Patent R N ER Erwin M. Riley and HarryE. Idoine, Phoenix, Ariz. Application September 2, 1950, Serial-No. 18$,Q23 11 Claims. (Cl. 37-90) This invention relates to and provides improvements in trenching machines. I

The conventional trenching machine; comprises a digger unit with an endless bucket line supported at the outer ends of two outward extending arms whose inner ends are pivotaliy attached to a vehicle. One-armis mounted above the other and a hydraulic piston and cylinder assembly is interposed therebetween for raising and lowering the trenching apparatus. i

T he digger unit of this conventional trenching machine is subject to abrupt and violent pitching, with the moving of the vehicle over-rough ground. i This frequently results in broken parts and in a general shortening of the life of the machine. Anothercommon fault is a ceaseless chattering of the arms.

-We have discovered that the pitching of the digger unit may be greatly reduced by lowering the inner pivot point of the upper arm. .But the lowering of this pivot point gives rise to newproblemsand necessitatesthe design and construction of a new combinedsupporting frame and lift assembly for thedigger unit.

The inner pivot of the upper a r moi theconventional trenching machine is necessarilyplaced relatively high to permit the raising of the digger unitfabove the ground. The lowering of this pivot point with the retention of the conventional arms and the hydraulic piston andlcylinder disposed therebetween would result in a trenchingmachine comparatively restricted in the height to which its diggerunit could be raised. i i

In our trenching machine, we have lowered the pivot point of the upper arm Without unduly limiting the height to which the digger unit .be raised; Generally speaking, the invention contemplates a trenching machine for attachment to a vehicle, the combination com prising an outwardly extending upper stabilize; arm pivotally supported at its inner end to the vehicle ar d an outwardly extending lower stabilizer arm pivotall y supported atits inner end to the vehicle at; a.p' oint lowenthanthe pivot of the upper stabilizer arm. Means is pivotally connected to the upper stabilizerarmand to thelower stabilizer arm atlocations spacedfrom theirpivoted ends for applying a spreading. force between fthetwo arms. An endless digger unit is disposed at the outer ends of the upper and lower stabilizer arms, the digger unit being pivotally connected to the-upper stabilizer arm and slidably and pivotally coupled to'the lower stabilizer arm so that relative movement betweenthe digger unit and the lower stabilizer arm isperrnitted in ayertical direction.

In one form of the invention, themeans for applying the force between the upper and lower stabilizer 1 arrils comprises a composite lower, stabilizer arm which ineludes as one component an outwardlyp gtending third arm pivotally supported atits inner end to thevehicle at the point lower than the pivot of the upper-stabilizer arm and inward of the pivot .of the othe'rcqmponent of the lower. stabilizer arm. The outer end othe third arm ,is coupled to the other lower. stabilizer arm couipount .upper arms 25. In otherlwords, the diggerunit is sus- Pettented Apr. 30,

at a point spaced vfrom/the pivoted end of the lower stabilizer arm. -,The twoends ofa hydraulic piston and cylinder assembly are respectively connected to the upper stabilizer arm and ,to thethird arm component, so that the hydraulic assemblyand thethird arm can be operated to apply force between the upper and lower stabilizer arms.

A frequent shortcoming of many trenching machines is the tendency to spill dirt back into the trench being .dug. We have overcome this shortcoming by providing in a trenching machineflofthe type having an endless .bucket line, the combination comprising a 'wheel having an open center and anearth conveyor extending transversely through this wheel. The bucket line rides over the wheel, dumping earthfrom-the vseveral buckets onto the transverse conveyor. We .havefound that a relatively large wheel is preferredbecause the dumping is smootherandmore gradual than with a smaller wheel.

:Preferably, the bucket line'is carried'at its opposite end by a second wheel spaced beneaththe open center wheel.

vIn our preferred embodiment, the two wheels are sprocket with one track. of the tractor removed;

;Eig.,2 is a longitudinal, section of the trenching machineoflFig. 1, takenalong line 2- 2 of that figure; and

Fig. 3 is a cross section through an upper drive sprocket o th trenching mac ine o i 'fhe trenching apparatus shown in the drawing is attached to a tractor 10, andcomprises two majorassemblies, a digger unit 1 11 anda combined supporting frame and lift assembly 12,and a transmission l l coupled to the epgine of the tractor.

The supporting frameand lift assembly .is made up of three pairs of rearwardly extending arms :25, 26, 40 which are pivotally connected attheir forward ends to .the tractor, two hydraulic piston and cylinder assemblies 16,721 slip clutch assembly 17, and requisite power transmission gears and chains. he transmission 14 through a chain; 18 drives a gear 19 affixed to one end of a shaft '21 which is journaled in an upright pedestal 23 bolted to the top. of; the tractor frame. The other end. of the shaft 21 carries {the slip clutch. assembly which in turn transmits power to a head shaft 22 of tl1e..digger unit through a drive- 1 chain 24.

;T.wo;of the pairs 25,.26 of rearwardlyextending arms,

couple and stabilizetheidigger unit to the tractor, with the arms of each pair being spaced from each other a .giistancesuthcientto. give operating clearance for the bucket line 27fwhichglies therebetween. Two relatively short-upright and spaced]bracketsQ29v .(see Fig. 2) are atliitedto the upper surface of a horizontally and transversely-disposed channelfbeam latl" of the digger frame and arepivotally connected .to the head shaft 22. The headshaft is journaled in the. trailing ends of the two pended-from the head shaft. The upper arms 25 are pivotallysupported at their forward ends on the-shaft 21 which carries theslip clutch assembly-17.

'Thelower pair of stabilizer arms,26, which are considerably shorter than ..the upper pair, are hinged at their trailing ends to the-digger unit by a shaft-32 of a slide assembly 53 which'is .slidably mounted on an upright beam 35 of the digger unit frame. v A shaft 37 is j ournaled i flange im fi tfdersriii m. thetreetbrshassis and pivotallytsupports the rem in n of the lower machines. dirt on the bucket ahead and frequently spills into the 'two lower stabilizer arms by two relatively short links 45 at corresponding points intermediate the forward ends and rnidpoints of the two stabilizer arms.

The two hydraulic piston and cylinder assemblies are respectively pivotally connected between the arms of the upper stabilizer pair and the arms of the third pair.

The piston shaft of each assembly is pivotally connected adjacent the midpoint of the respective upper stabilizer arm near the pivot end of the respective arm and the cylinder of each assembly is pivotally connected adiacent the forward end of the respective third arm.

The digger unit illustrated has an endless bucket line which is carried at its respective ends over two relatively large, upper, coaxially spaced drive sprockets 49 and two smaller, coaxially spaced, lower idler sprockets 50. We have found that by employing upper sprockets which are relatively large, the dumping of the several buckets as they pass over the upper sprockets is smooth and gradual and free of the quick snap common to other trenching A quick snap dumping of a bucket throws trench being dug. The lower idler sprockets, instead of having the conventional ring of circumferential teeth, have spaced sets of three teeth. These sets of teeth are spaced at intervals around the circumference of each lower sprocket at proper distances to mesh with the sev-,

eral links 61 or" the bucket line.

The frame of the digger includes two downwardly converging elongated beams 35, 51 which are spaced apart near their upper ends by a cross beam 52. The lower ends of the two elongated beams are held together by two plates 54 (Fig. 2) fastened between respective sides of the two beams. A shaft 56 journaled in the two plates supports at its opposite ends the two idler sprockets 50.

The beam 35 supports at its upper end the transverse channel beam 30, previously described. Two triangularshaped gusset plates 57 (Fig. 2) are welded to opposite sides of this beam and to the underside of the overlying channel beam 36. A beam 58 of the same length as the horizontal and transversely disposed channel beam 30 lies parallel to and in the same horizontal plane as such beam and is affixed to the upper end of the beam 51 of the digger frame.

Each of the upper drive sprockets has an outer ring 60 of outwardly projecting teeth which mesh with the several links 61 of the bucket line and also a ring of internal teeth 63. Each sprocket (seen best in thecross section of Fig. 3) also has an internal circumferential inwardly projecting flange 64, spaced from the internal teeth.

Each of the two drive sprockets is supported by three idler rollers 66, 67, 68 and is driven by a separate pinion gear 69. identically functioning parts associated with the two sprockets are identified by the same numbers. The corresponding rollers of the two sprocket assemblies are mounted on common shafts. The two pinion gears and the two rollers 66 are affixed to the head shaft 22 (Fig. 2) which hinges the digger unit to the upper pair of stabilizer arms. A shaft 70 journaled in two spaced brackets 7t fastened to the top of the horizontal beam 58 (inside of the circumference of the drive sprockets) carries the rollers 67 at its opposite ends, and a roller shaft 73 rotatably mounted on the top of the'cross beam 52 mounts the rollers 68. The two pinion gears respectively mesh with the internal teeth of the two drive sprockets,

with the several rollers rotatably engaging the inwardly projecting flanges 64 of the two sprockets.

Power is supplied to the digger unit from the transmission 14 coupled to the tractor through chain 18, shaft 21, slip clutch 17 and the drive chain 24 to the head shaft 22. The two pinion gears afllxed to the head shaft mesh with the internal teeth of the two upper sprockets, driving these sprockets whose outer circumferential teeth engage and drive the bucket line.

The two parallel, horizontal and spaced beams 58, 30 support at their opposite ends a driving roller 75 and an idler roller 76 of an endless belt conveyor 77. The belt of the conveyor is horizontally disposed and extends transversely of the digger inside of. the two drive sprockets, with the two ends of the conveyor spaced some distance from the sides of the digger. The conveyor is driven from a sprocket 78 mounted on an outer end of the head shaft through a two-way gear box 79 afiixed to the digger frame and a chain or belt 80. By changing the direction of rotation of the gears of the two-way gear box, earth carried by the conveyor may be dumped on either side of the trenching machine.

An elongated, narrow guide plate 32 fastened to the bottom of the digger frame beam 35 runs the length of and is spaced from this beam by several cleats 83. The plate continues upward from the upper end of the beam and is bent down and over the head shaft 22, forming a chute for channeling the earth dumped from the buckets onto the conveyor belt. A second chute 87 (Fig. 1) is fastened to the opposite side of the digger frame for the same purpose. The guide plate lessens 'the slapping of the bucket line which rides thereon.

To raise the digger unit, fluid under pressure is introduced through a common line (not shown) to the two hydraulic cylinders through connections 89 from a pump and reservoir (neither shown), forcing the upper stabilizer arms 25 upward and the third pair of arms 40 downward. The lower stabilizer arms 26 are pulled downward by the third pair, and their trailing ends which are slidably held to the beam 35 continue in this direction until the slide assembly engages a stop 99 affixed to the beam. At this time the force exerted upward at the rear end of the upper stabilizer arms being greater than force acting downward at the stop causes the lower stabilizer arms and the third pair to move upward. Continued introduction of fluid under pressure to the cylinders raises the digger unit out of the trench. To lower the digger unit, hydraulic pressure is removed and the weight of the unit causes the digger to descend.

The trenching machine described employs three pairs of arms; however, the several features of the invention could be incorporated in a trenching machine having three single arms and a single hydraulic piston and cylinder assembly.

We claim:

1. In a trenching machine for attachment to a vehicle, the combination comprising an outwardly extending upper stabilizer arm pivotally supported at its inner end to the vehicle, an outwardly extending lower stabilizer arm pivotally supported at its inner end to the vehicle at a point lower than the pivot of the upper stabilizer arm, an outwardly extending third arm pivota'lly supported at its inner end to' the vehicle at a point lower than the pivot of the upper stabilizer arm and inward of the pivot of the lower stabilizer arm, the outer end of the third arm being coupled to the lower stabilizer arm at a point spaced from the pivoted end of the lower stabilizer arm, a hydraulic piston and cylinder assembly with its two ends respectively connected to the upper stabilizer arm and to the third arm, an endless digger unit disposed at the outer ends of the upper and lower stabilizer arms, means pivotally connecting the digger unit to the upper stabilizer arm and means slidably connecting the digger unit to the lower stabilizer arm.

2. In a trenching machine for attachment to a vehicle,

,the combination comprising an outwardly extending upper stabilizer arm 'pivotally supported at its inner end menace to the vehicle,.an outwardly vextendinglower stabilizer arm pivotally supported at its inner :endlo the vehicle at a point lower than the pivot of. .thenpperstabilizer .arm, an outwardly extending third arm,pivotally supported at its inner end to the veliicle at a point lowerthanathe pivot of the upper stabilizer arm and inwardof the pivot of the lower stabilizer arm, withtheouterend of the third arm being coupled to the undersideof: the lower stabilizer arm at a pointspaced from the, pivoted end .ofthe lower stabilizer arm, means connected to the .upper stabilizer arm and to'the thirdarm at locationstspaced from their pivoted ends forapplyinga force betweenthe two .arms, an endless digger unit disposed attheouter endsofthe upper and lower stabilizer arms,meansapivotally.connecting the digger unit to the upper.stabilizertarm,vand means slidably coupling the digger unitto the lower stabilizer arm so that relative movementtbetweentthe diggernnit and the lower stabilizer arm is permitted-inavertical direction.

3. In a trenching machine for-attachment to avehicle, the combination comprisingtan outwardlyextendingnpper stabilizer armpivotally supported ;at its.inner endto the vehicle, 7 an outwardly extending-lower stabilizer: arm pivotally supported at its innerend :to thewehicle ataa point lower than the :pivotof .theupperzstabilizerarm, an outwardly extending third arm pivotally. supported at its inner end to the vehicle at a point lower than the pivot of the upper stabilizer arm and inwardof the pivot of the lower-stabilizer arm/theouterendof the third arm being coupled to thelower stabilizer'arm at a point spaced from the pivoted end of the lower stabilizerarm, means connected tothe upper stabilizer armand the third arm at points intermediate their midpoints' and pivoted ends for applying a-force" between them, an endless digger unit-disposed at--the outer ends of the-upper and lower stabilizer arms, means suspending the digger unit from the upper stabilizer arm, and means slidably coupling the digger unit to the lower stabilizer arm.

4. In a trenching machine for attachment to a vehicle, the combination comprising an outwardly extending upper stabilizer arm pivotally supported at its inner end to the vehicle, an outwardly extending lower stabilizer arm pivotally supported at its inner end to the vehicle at a point lower than the pivot of the upper stabilizer arm, an outwardly extending third arm pivotally supported at its inner end directly beneath the pivot of the upper stabilizer arm, and inward of the pivot of the lower stabilizer arm, the outer end of the third arm being beneath and coupled to the lower stabilizer arm to a point intermediate of the lower stabilizer arms pivoted end and middle, a hydraulic piston and cylinder assembly interposed between the upper stabilizer arm and the third arm, the piston and cylinder being respectively pivotally connected to the arms at points intermediate their midpoint and their pivoted ends, an endless digger unit disposed at the outer ends of the upper and lower stabilizer arms, and means coupling the digger unit to the ends of the upper and lower arms so that the spacing between the ends of the arms is adjustable.

5. In a trenching machine for attachment to a vehicle, the combination comprising an outwardly extending upper stabilizer arm pivotally supported at its inner end to the vehicle, an outwardly extending lower stabilizer arm pivotally supported at its inner end to the vehicle at a point lower than the pivot of the upper stabilizer arm, an outwardly extending third arm pivotally supported at its inner end to the vehicle at a point lower than the pivot of the upper stabilizer arm and inward of the pivot of the lower stabilizer arm with the outer end of the third arm below the lower stabilizer arm, a short link hinged respectively at its opposite ends to the outer end of the third arm and to the lower stabilizer arm at a point spaced from its pivoted end, a hydraulic piston and cylinder assembly with its two ends respectively connected to the upper stabilizer arm and to the third arm, an endless digger ,unit disposed at zthepouter ,ends-\. of :the upper and lower.,stabilizer arms, means suspending-the diggenunit from the upperwstabilizer ,arm and ,rneans coupling the digger unit. to thellower stabilizer arm sothatthe spacing between theends .of vtherupper and :lower stabilizersza ms is-adjustable. v

[6. ,In-a trenching machine for attachment,to,a,vehicle, the combination comprising ,an outwardly extending upper stabilizer varm pivotallysupported ,at itslinner ,endlto the vehicle, an-outwardly extendinglower stabilizer arm pivotally supported, at its inner end ,:t0 the vehicle, at a pointlower than ,the pivot ofthe,upperstabilizerarm, an outwardly "extending ,third arm pivotally supported at its inner ,endhtofthe vehicle -.at ,apoint lower .thanrihe pivot of the upperstabilizer.arm-,andlinwardly,andf'lower than the .pivot. of {thelower stabilizer 'arm, a,fshort'link hinged respectively ,satvits opposite ,endsrto theouter end of, the. third .arm and to the, lower stabilizer arm between its midpoint and pivoted end, ;a hydraulic piston a d cylinder assembly pivotally "connected, respectively ,at, its two endslto'. the ,uppertstabilizer, anmflbetween its midpoint and pivoted i end .and s to the third armv between itsrmidpoint and pivoted .end, an 1 endless digger unit ;=disposed at the ;outer endso'f the upper and Q. lower stabilizer arms, means pivotally connecting the digger ,;.unit to the upper stabilizer arm, andmeans coupling the digger unit tothe I lower stabilizer ,armlsothat .relative movement between the digger .unit .and the loWerstabilizer arm. ispermitted in- ,a. direction transverse, to .the longitudinal axis, of the lower. stabilizer, arm.

7 7. In artrenchingemachine -for, attachmentto .ta:vehicle, thecombination comprising, anoutwardly extendingupper stabilizer, arm pivotally supported at its inn,er end :tothe vehicle, nan outwardly. ,..extending flower stabilizer arm pivotallymupporte'drat, .its inner: end; to the vehicle at a point lowerthan the, pivot of -the.uppler,stabilizer arm, an outwardly extending third arm pivotally supported at its inner end to the vehicle at a point beneath and in vertical alignment with the pivot of the upper stabilizer arm and inward from and lower than the pivot of the lower stabilizer arm, a short linkage hinged respectively at its opposite ends to the outer end of the third arm and to the under side of the lower stabilizer arm between its midpoint and pivoted end, a hydraulic piston and cylinder assembly pivotally connected respectively at its two ends to the upper stabilizer arm between its midpoint and pivoted end and to the third arm between its midpoint and pivoted end, an endless digger unit disposed at the outer ends of the upper and lower stabilizer arms, means pivotally connecting the digger unit to the upper stabilizer arm, and means coupling the digger unit to the lower stabilizer arm so that relative movement between the' digger unit and the lower stabilizer arm is permitted in a direction transverse to the longitudinal axis of the third arm.

8. In a trenching machine for attachment to a vehicle, the combination comprising an outwardly extending upper stabilizer arm pivotally supported at its inner end to the vehicle, an outwardly extending lower stabilizer arm pivotally supported at its inner end to the vehicle at a point lower than the pivot of the upper stabilizer arm, an outwardly extending third arm pivotally supported at its inner end to the vehicle at a point lower than the pivot of the upper stabilizer arm and inward of the pivot of the lower stabilizer arm, the outer end of the third arm being coupled to the lower stabilizer arm at a point intermediate of its pivot end and midpoint, a

hydraulic piston and cylinder assembly interposed and,

pivotally connected between the upper stabilizer arm and the third arm, and a digger unit disposed at the outer ends of the upper and lower stabilizer arms, said digger unit having a relatively large upper sprocket, a smaller lower sprocket, an endless bucket line carried at its respective two ends over the two sprockets, an endless conveyor extending through the upper sprocket transversely of the sprocket and bucket line, means pivotally'connecting the digger unit to the upper stabilizer arm, and means coupling the digger unit to the lower stabilizer arm so that relative movement between the digger unit and the lower stabilizer arm is permitted in a vertical direction.

9. ,In a trenching machine for attachment to a vehicle, the combination comprising an outwardly extending upper stabilizer arm pivotally supported at its inner end to the vehicle, an outwardly extending lower stabilizer arm pivotally supported at its inner end to the vehicle at a point lower than the pivot of the upper stabilizer arm, means pivotally connected to the upper stabilizer arm and to the lower stabilizer arm at locations spaced from their pivoted ends for applying a spreading force between the two arms, the linear distance between the pivoted inner end of the upper stabilizer arm and its connection with the spreadingmeans being greater than the corresponding distance related to the lower stabilizer arm, an endless digger unit disposed at the outer ends of the upper and lower stabilizer arm, means pivotally connecting the digger unit to the upper stabilizer arm, and'means slidably and pivotally coupling the digger unit to the lower stabilizer arm so that relative movement between the digger unit and the lower stabilizer arm is permitted in a vertical direction.

10. A trenching machine having a frame, an upper lever arm, a pivotal connection between one end of said upper lever arm and said frame, a bucket chain line frame, a pivotal connection between the other end of said upper lever arm and the upper end of said bucket chain line frame, a lower lever arm, a pivotal connection between one end of said lower lever arm and said frame, a sliding connection member, means for pivotally mounting said sliding connection member on the other end of said lower lever arm, a guide flange on said bucket chain line frame slidingly engaged and supported in said sliding connection member, an extensible and retractable power 8 actuator, a pivotal connection between one end of said power actuator and an intermediate point on said lower lever arm, and a pivotal connection between the other end of said power actuator and an intermediate point on said upper lever arm.

11. A trenching machine having a frame, an upper lever arm, a pivotal connection between one end of said upper lever arm and said frame, a bucket chain line frame, a pivotal connection between the other end of said upper lever arm and the upper end of said bucket chain line frame, a lower lever arm, a pivotal connection between one end of said lower lever arm and said frame, a sliding connection member, means for pivotally mounting said sliding connection member on the other end of said lower lever arm, a guide flange on said bucket chain line frame slidingly engaged and supported in said sliding connection member, an extensible and retractable power actuator, a pivotal connection between one end of said power actuator and an intermediate point on the lower lever arm, and a pivotal connection between the other end of said power actuator and an intermediate point on the upper lever arm, the distance between the intermediate pivotal connection of the upper lever arm and the bucket chain line frame being less than the distance between the intermediate pivotal connection of the lower lever arm and the bucket chain line frame.

References Cited in the file of this patent I UNITED STATES PATENTS 1,744,942 

